Constraining the magnetic field geometry of the millisecond pulsar PSRJ0030+0451 from joint radio, thermal X-ray, and γ-ray emission

Pétri, J.; Guillot, S.; Guillemot, L.; Cognard, I.; Theureau, G.; Grießmeier, J. M.; Bondonneau, L.; González-Caniulef, D.; Webb, N.; Jankowski, F.; Kravtsov, I. P.; McKee, J. W.; Carozzi, T. D.; Cecconi, B.; Serylak, M.; Zarka, P.

Abstract

Context. With the advent of multi-wavelength electromagnetic observations of neutron stars - spanning many decades in photon energies - from radio wavelengths up to X-rays and γ-rays, it has become possible to significantly constrain the geometry and the location of the associated emission regions. Aims. In this work, we use results from the modelling of thermal X-ray observations of PSR J0030+0451 from the Neutron Star Interior Composition Explorer (NICER) mission and phase-aligned radio and γ-ray pulse profiles to constrain the geometry of an off-centred dipole that is able to reproduce the light curves in these respective bands simultaneously. Methods. To this aim, we deduced a configuration with a simple dipole off-centred from the location of the centre of the thermal X-ray hot spots. We show that the geometry is compatible with independent constraints from radio and -ray pulsations only, leading to a fixed magnetic obliquity of α ≈ 75° and a line-of-sight inclination angle of ζ ≈ 54°. Results. We demonstrate that an off-centred dipole cannot be rejected by accounting for the thermal X-ray pulse profiles. Moreover, the crescent shape of one spot is interpreted as the consequence of a small-scale surface dipole on top of the large-scale off-centred dipole.

Citation

Pétri, J., Guillot, S., Guillemot, L., Cognard, I., Theureau, G., Grießmeier, J. M., …Zarka, P. (2023). Constraining the magnetic field geometry of the millisecond pulsar PSRJ0030+0451 from joint radio, thermal X-ray, and γ-ray emission. Astronomy and Astrophysics, 680, Article A93. https://doi.org/10.1051/0004-6361/202346913

• Journal Article Type: Article
• Acceptance Date: Sep 5, 2023
• Online Publication Date: Dec 15, 2023
• Publication Date: Dec 1, 2023
• Deposit Date: Jan 8, 2024
• Publicly Available Date: Jan 9, 2024
• Journal: Astronomy and Astrophysics
• Print ISSN: 0004-6361
• Electronic ISSN: 1432-0746
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 680
• Article Number: A93
• DOI: https://doi.org/10.1051/0004-6361/202346913
• Keywords: stars: neutron; pulsars: individual: PSR J0030+0451; stars: rotation; magnetic fields; gamma rays: stars; X-rays: stars
• Public URL: https://hull-repository.worktribe.com/output/4501029